The present invention relates to an image forming apparatus, in which a charging means, an image exposure means and a developing means are arranged around an image forming body, a toner image is formed on the peripheral surface of the image forming body when the image forming body is rotated, and then, the toner image is transferred onto a recording sheet.
In an image forming apparatus, specifically, in a conventional electrophotographic copier for office use, or an image recording apparatus used for terminal equipment, the following apparatus, for easily carrying out jam clearance operations or maintenance operations, are widely known. There is an apparatus in which a cartridge for incorporating a photoreceptor and developing units therein, is removed when a side door of the apparatus main body is opened, and the surface of the conveyance path for the transfer material is exposed. Further, there is a clamshell type apparatus in which the apparatus main body is separated into an upper and a lower main body, and the surface of the conveyance path for the transfer material is exposed.
However, when the apparatus is structured such that the photoreceptor, developing units, etc., are removed from the apparatus, there is potential danger in which the removed units are touched by the operator's hands or other units and are stained, and specifically, in the case of developing units, there is a possibility in which foreign matter adheres to a developing sleeve, resulting in image degradation.
Further, in a clamshell type apparatus, the conveyance path of the recording sheet is used as a separation line to open and close the upper portion of the apparatus with respect to the lower portion of the apparatus. In this case, normally, it is necessary to separate the photoreceptor from the transfer unit for easier jam clearing. As a result, a portion of the photoreceptor which is opposed to the transfer unit, is largely exposed, and a possibility occurs in which operator's hands easily touch the portion, and the surface of the photoreceptor is stained. Further, in the case of a color image forming apparatus, since a plurality of developing units are incorporated into an upper main body, the weight of the upper main body is increased, and thereby, the ease of operation decreases, and the strength and rigidity of the whole apparatus main body are also decreased. Therefore, when an image is formed, the apparatus is more easily and adversely affected by oscillations, which is a problem.